New details about troubles at Zenefits may help explain why Fidelity drastically slashed its valuation on the human resources software company.

The Wall Street Journal reported on Friday that the Y Combinator alumnus led by CEO Parker Conrad has missed ambitious revenue targets, triggering cost-cutting moves that include a hiring freeze in some departments and some pay cuts.

The Journal cited unnamed people in its story who said that dozens of people, including at least eight executives, have left or been fired.

The news follows a report on Thursday that said Fidelity marked down the value of its investment in Zenefits by 48 percent, just months after it and other investors backed the company in its most recent funding round at a valuation of $4.5 billion.

In January, Conrad predicted that Zenefits would grow its $20 million in annual recurring revenue to $100 million in the next year.

But the Journal's sources said the company only had lined up $45 million by August and Its work force had swelled to 1,640 from 500 the year before. That reportedly triggered the cost-cutting moves.

Long before that, in March, the Journal's sources said that Zenefits decided to stop paying employees for unused vacation time. It said that some former employees now claim they weren’t paid for vacation time accrued before the change, as required by California law.

That's a particularly damaging claim for a company that offers free human resources software to small and mid-sized businesses. It makes its money on commissions it gets from selling them insurance.

Zenefits spokesman Kenneth Baer told the Journal that Zenefits is still growing at a very rapid pace: “The demand we are seeing from thousands of small businesses who want these HR burdens to go away is so big that Zenefits is growing very fast, quadrupling its annual recurring revenue over the past 12 months.”

Shortly after raising its big round of funding early this year, Zenefits got into an ugly legal battle with benefits giant ADP. It settled that fight late last month.

The company has raised about $583 million since it was founded in 2013. In addition to Fidelity, its backers include Silicon Valley investors Andreessen Horowitz, Institutional Venture Partners and Venrock.